I'm a co-founder of NorthBridge Energy Partners, LLC., a consulting firm that helps companies connect assets to power grids. I'm also a former Senior VP of Energy Technology Services for Constellation NewEnergy, Inc., and have 20+ years of experience in the energy industry. I've written for the Boston Business Journal, Mass High Tech and several other online industry publications. I have a B.A. from Williams College and a Masters from Tufts University’s Fletcher School.

Although the initial numbers are small, the trend is worth watching, as some of the pieces of the electric car puzzle are finally fitting together. Nissan just announced that it will ramp up U.S. assembly of the 2013 model year all-electric LEAF at its manufacturing plant in Smyrna, Tenn. The Leaf will be made in the same plant, on the current Altima and Maxima line, and next to Nissan’s gasoline-powered vehicles, and next door to the largest lithium-ion automotive battery plant in the U.S. The goal is to lower costs and appeal to a broader spectrum of customers. In all of 2012, Nissan sold 9,819 Leafs with about 19,500 on the road in the US, and 50,000 worldwide. And of course, Toyota has come out with its Plug-in hybrid Prius, selling 12,750 units in the last last year alone. In fact the total plug-in sales tripled from just over 17,500 in 2011 to about 53,000 in 2012.

Meanwhile, other entrants from the major car companies – from BMW to Mitsubishi – are joining the market. And there are the pure plays as well, such as Fisker and Tesla. The latter’s Model S – at $58,570 and priced competitively among relevant high-performance peers – just won 2013 Motor Trend Car of the Year, with the magazine commenting “The 2013 Motor Trend Car of the Year is one of the quickest American four doors ever built. It drives like a sports car, eager and agile and instantly responsive. But it’s also as smoothly effortless as a Rolls-Royce, can carry almost as much stuff as a Chevy Equinox, and is more efficient than a Toyota Prius…By any measure, the Tesla Model S is a truly remarkable automobile, perhaps the most accomplished all new luxury car since the original Lexus LS 400…At its core, the Tesla Model S is simply a damned good car you happen to plug in to refuel.” (It’s that kind of comment that suggest that alternative technologies in transportation have truly arrived. They are no longer green curiosities – they are great vehicles).

Tesla not only makes a great car, but it seems to have turned the corner on production volumes as well. In Q3 of last year, they went from making 5 cars per week to 100. By November, they had scaled to 200 cars per week, and have a goal of 20,000 for 2013.

So the era of the electric car appears to be dawning upon us. But what about the charging side of the equation? What does that mean for our electric power grid? The first thing to understand is that electric vehicle adoption has been hampered by a fear of running out of electricity, so-called ‘range anxiety,’ since they don’t get the hundreds of miles per fill-up one gets with a gasoline-powered vehicle. The lithium ion batteries simply do not yet have that capacity. To account for this, networks of charging stations are being built across North America. There are standards emerging for these chargers, but there is still some confusion among options.

For its part, the electric energy utility NRG, is taking a dramatic and aggressive approach to move into this space. Through eVgo they offer network charging, where users have the option to pay a fixed monthly fee of as little as $19/month to charge up at DC Fast Charger sites, getting 50 miles of range in 15 minutes, ands they also provide an option for a slow charge as well. They also offer a program to plug in for extended times (at work places or multi-family sites) of 4-8 hours. Finally, eVgo will set up a home charging station for the individual user, with plans at $59/month. Their network started in the Houston and Dallas locations, but they are now extending into California and the Northeast. In California alone (as part of a settlement with the State over issues occurring suring the CA energy crisis over a decade ago) NRG has agreed to build and operate infrastructure for at least 200 fast-charging (480 volt) stations, and a minimum 10,000 level 2 (240 volt) stations in businesses and multi-unit dwellings.

The home charging infrastructure is also getting cheaper and more easily accessible. Lowes, Best Buy, and others now offer charging stations from manufacturers such as Schneider, Leviton, and GE in the $750-1000 cost range.

There are currently over 15,000 charging stations across the U.S., with many of them 240 volt rapid chargers. With that kind of draw on electricity demand, the obvious question is what will happen to peak demand. Will EV drivers draw so much power during driving hours (rush hour, or mid-day), that it contributes to overall peak demand? If so, this would be precisely the opposite of the reason the utilities originally hailed electric cars. The thought ten years ago was that they would mostly be charged at night, filling in the valley of low off-peak demand, and thus allowing more kilowatt-hours to flow across the same infrastructure. However, with rapid charging at higher voltages and kW levels, the dynamic could potentially push exactly the other way.

Let’s look at the actual charging capacities to get a sense of the potential magnitude: In the extreme, Tesla is offering a super high voltage charging opportunity, providing a range of 150 miles to its Model S 85 kilowatt-hour (kWh) battery in about 30 minutes. The charge capability is 480 volt, with a maximum 90 kilowatt (kW) draw. That level of voltage and capacity is quite significant. To put it in perspective, for planning purposes the California Energy Commission assumes the average residential household to have a peak ranging between 1.8 and 2.4 kW. So the supercharge station with 90 KW essentially packs the punch of about 40 households worth of peak demand. Looked at another way, a Sears/Kmart store might have 300 kW of peak demand, just over 3x what a single car battery charge would draw for a short period.

The other charging stations out there don’t pack quite the same firepower, but the standard level 2 240-volt chargers can draw up to 19 kW during periods lasting from 30 minutes to 3 hours. With increasing numbers of these stations, what is the potential impact to the electric grid?

Deloitte looked at precisely this issue recently, in its report Charging Ahead: The Last Mile. They interviewed numerous utility planners summarized “Surprisingly, we found that in general, the electric utility infrastructure is already prepared to meet the President’s 2015 challenge. Our research revealed that utilities will not likely need to upgrade or expand transmission or generation capacity in the next ten years specifically to meet electric demand from EVs at projected adoption rates….However, the research did identify near-term impacts to the electric infrastructure that deserve further study at the local distribution level, ‘the last mile,’ including possible clustering of EVs on low-capacity distribution transformers, such as 25 kVA , and the potential impact on local transformers of any capacity if clusters of EVs charge simultaneously during hours of peak electric demand. The research also showed that utilities are studying and addressing these impacts”.

The major findings:

1) Almost all the utilities surveyed had studied the impacts of EVs on their supply infrastructure, with the most common focus being on distribution level impacts, home charging stations, peak-hour charging, and research into transformers.

2) Nearly three-quarters of the utilities do not foresee an impact on the need for new generating capacity, and two-thirds feel they have adequate transmission infrastructure in place. Just over a tenth raised concerns about transformer overloading.

3) However, fully half indicated they are not notified when a ratepayer purchases an electric vehicle in their service territory (a few areas, such as California are working to design notification processes, and the Texas utilities have proposed a law requiring such notification).

For now, at least, any infrastructure problems appear to be at the local level. The concern of some in that area has to do with – ironically – peak demand at night. If a number of 240 volt chargers – which could recharge a car in 2-3 hours – were to be deployed in the evening, during off-peak rates designed to take peak demand from the grid, one might burn out the street-level transformers. “Many of these are undersized and designed to cool at night. Without time to cool, sustained excess current will eventually cook a transformer’s copper windings, causing a short and blacking out the local loads it serves,” according to an article in the IEEE.

This problem may be more than just theoretical. Data concerning the habits of EV owners in an Austin, TX suburb, indicated that over a two month period the residents generally tended to recharge at the same time – when returning from work. This also happened to be when many residents were also turning on air conditioning and other appliances.

At this point, it’s pretty evident that electric cars are coming into vogue and that at least in the short-term, we probably won’t have major difficulties absorbing them into the system. It’s also clear that they may have profound implications for the power grid in the longer-term, based on behavioral issues, tariff policies, emerging technology, and economics. This trend bears watching, and the utilities should be paying close attention to both volumes sold and user behavior. As electric and transportation systems collide, unexpected outcomes should not surprise us.

Post Your Comment

Post Your Reply

Forbes writers have the ability to call out member comments they find particularly interesting. Called-out comments are highlighted across the Forbes network. You'll be notified if your comment is called out.

Comments

On the contrary, Tesla seems to think they’ll generate more power than is used, and apparently that’s how they’re financing the operation. Of course to really answer this question you have to make an assumption about how frequently these superchargers will be used which is very difficult to do at this point since there are only ~9 superchargers and a few thousand Model S in existence.

Home charging stations are just fine for all-electrics, whatever size battery they have. Just because someone has an EV with a bigger battery doesn’t mean he’ll drive any more on average than the next guy. Since you plug your car in every night you only need to replenish one day’s driving at a time.

We have high powered charging units for these larger kwh batteries…so it can be done overnight with no problem, and honestly my typical daily commute is less than 80 miles/day. So it will charge for a short amount of time. There are many superchargers throughout the country, and by the end of this year/next year, we could actually go across the country with free charging at these stations!

would it not be possible to create a series of ‘cats eyes’ that both illuminate lanes and also send wireless charging to the battery so when driving at speeds on the british motor ways it can top up the cars battery enough to keep it running till ultimatly having its ‘ long life charge’?

Residential Peak of 2.4 KW? Really? That is one burner on my stove. Guess if I turn on my clothes dryer and cook dinner at the same time, I might burn out the power grid. Mr Detwiler, how do you explain this?

Colin (Mr. Perry) – You are right – a stove can go to 2000+ watts. A lightbulb is 60. Hairdryers are also big draws and can go to 1300 – 1800 watts. So be careful when you use the latter. I do believe I said average.

You and I even each other out: I have a gas dryer and a gas range. And I don’t use my hairdryer to heat my house or warm my food. Together, we probably do get close to that average of 2.4 kW. As far as my capacity charge, I don’t even get close. So that is how I explain it. Hope I sold you.

Colin – I had to call for additional back up: http://www.toolbase.org/PDF/CaseStudies/ResElectricalEnergyUseData.pdf check out pages 25 – 27. Max KW draw over an hour in California utilities ranges from just under 2 KW to about 2.25 kW unless electric space heating is involved. then the number jumps over 5 kW. In Baltimore, non-space heating peak is around 2.35. W/ space heating, it more than doubles.

Colin – I’d like to go with you on this one, but I cannot. See page 18 of most recent CA demand forecasts: http://www.energy.ca.gov/2012publications/CEC-200-2012-001/CEC-200-2012-001-CMF-V2.pdf PG&E high peak kW per avg household is 2.35 kW, and they show it declining to just below 2 kW until 2018. Page 44 SCE projection shows a pretty similar story. BTW CHECK OUT their projections for electric vehicle use on p. 27. It explodes (I should have used it in my article)!

Peter, All interesting and the utilities seem to believe it will not impact them much. I find it funny though on page 10 of the mentioned article, PG&E lists peak demand per capita around 1.7 kW and on page 18 lists peak demand per household at 2.35kW. I guess they expect most of us to live alone, yet they expect around 2.7 persons per household.